According to conventional devices, the segmented part has teeth which project from a base, these teeth forming grooves with one another inside which coils surrounding the teeth are disposed.
The use of elementary laminated cores to form segmented parts of the motor offers a variety of known advantages. In particular, it is possible to produce linear motors whose coil-carrying armature has different lengths but is made of the same elementary laminated cores. However, the production of motor components carrying coils, made up of a plurality of elementary components, requires rigid affixation devices for these elementary components. In particular, to ensure operability of the motor, the elementary components must be held together at their transition points in order to prevent air gaps from forming between these elementary components. Furthermore, the interface surface to the motor must have excellent planarity in order to ensure satisfactory dissipation of the heat generated inside the motor. In the following text, the armature is treated as mobile component only, but example embodiments of the present invention apply to motors having a stationary armature as well.
U.S. Pat. No. 4,665,329 describes a linear motor whose mobile component carrying the coils is made up of a segmented part. The segmented part is formed by a plurality of elementary laminated cores, which form elementary parts. To join individual elementary parts, grooves are placed on the longitudinal surface of the elementary parts on the side opposite the teeth, near the ends. Connecting parts are inserted into two adjacent grooves in the region of each transition tooth. The joining of the elementary parts described in U.S. Pat. No. 4,665,329 has various disadvantages. First of all, it requires the use of specific affixation devices. Furthermore, the two partial teeth forming a transition tooth are not held together since the affixation is implemented only on the top surface of the segmented part located opposite the teeth. In particular, in response to mechanical loading of the segmented part, it is easily possible for the teeth to move apart. This has a detrimental effect on the stability of the mobile part and it also increases the reluctance effect of the motor. In addition, this joining method requires very narrow dimensional tolerances for the mechanical components, which makes them expensive.